Question

sa sa afle numarul x,y,z stiind ca. x:y=3. ;x:z=6 ;x+y+z=90

Answer 1

x/y=3 => y=x/3
x/z=6 => z=x/6
x+y+z=90
x+x/3+x/6=90
6x+2x+x=540
9x=540
x=60
y=20
z=10

Answer 2

x:y=3
x:z=6
x+y+z=90

y=x:3
z=x:6

x+x:3+x:6=90
x+$\frac{x}{3}$+$\frac{x}{6}$=90
aducem la aceiasi baza adica 6 si vom avea
$\frac{6x}{6}$+$\frac{2x}{6}$+$\frac{x}{6}$=90
$\frac{9x}{6}$=90
$\frac{3x}{2}$=90
3x=2·90
3x=180
x=180:3
x=60
y=60:3
y=20
z=60:6
z=10
verificare 60+20+10=90